I believe this is still present in 16.04. Specifically I become CPU bottlenecked (100% on one core by /usr/lib/apt/methods/http) when downloading packages within AWS EC2 instances (better bandwidth with download servers there). Besides the issues around locking up a core, this makes several processes take noticeably more time than they should.
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to apt in Ubuntu. https://bugs.launchpad.net/bugs/1123272 Title: high cpu usage on download (not optimised SHA256, SHA512, SHA1) Status in apt package in Ubuntu: Confirmed Bug description: http process takes about 20% on intel i5-3317. Here is output of ps aux: root 4309 21.7 0.0 37108 2344 pts/2 S+ 18:17 0:01 /usr/lib/apt/methods/http it can be easy reproduces with "apt-get download firefox-dbg" or any other upgrade realted command. The reason of this overhead are this functions: 22,34% http libapt-pkg.so.4.12.0 [.] SHA256_Transform(_SHA256_CTX*, unsigned int const*) 14,81% http libapt-pkg.so.4.12.0 [.] SHA512_Transform(_SHA512_CTX*, unsigned long const*) 8,11% http libapt-pkg.so.4.12.0 [.] SHA1Transform(unsigned int*, unsigned char const*) 5,62% http libapt-pkg.so.4.12.0 [.] MD5Transform(unsigned int*, unsigned int const*) libapt uses own implementation of this hasches without any optimisation. Are there any reason why libapt do not use openssl? Beside current version of openssl has AVX optimised SHA* implementations. ProblemType: Bug DistroRelease: Ubuntu 13.04 Package: apt 0.9.7.7ubuntu1 ProcVersionSignature: Ubuntu 3.8.0-4.9-generic 3.8.0-rc6 Uname: Linux 3.8.0-4-generic x86_64 ApportVersion: 2.8-0ubuntu4 Architecture: amd64 Date: Tue Feb 12 18:12:33 2013 InstallationDate: Installed on 2012-09-13 (152 days ago) InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64 (20120913.1) MarkForUpload: True ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=de_DE.UTF-8 SHELL=/bin/bash SourcePackage: apt UpgradeStatus: Upgraded to raring on 2013-02-06 (5 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/apt/+bug/1123272/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
